Many cotters, cotter pins and cotter keys are known in the art. However, none of the prior art designs are known to have the structure and features of the present invention. The function of a cotter is to provide a means for locking a pin, post or stud in an opening. Common applications of the cotter can be found in the agricultural and construction industries. A cotter is often utilized to retain a pin within openings formed in to or more machine parts. For example, a disc may be attached to a tractor with a three-point hitch. At each hitching point a pin passes through openings in the hitch and disc frame. Each pins is retained in its respective opening with a cotter.
To make a cotter a more effective tool for retaining pins, posts or studs in openings, the cotter should have the capability to be easily connected and disconnected from its mating pin, post or stud. In addition, it is highly desirable that the cotter maintains its installed position despite the operating environment of the equipment to which it is attached.
One of the drawbacks of known cotters, such as the traditional spring clip cotter, is that prior art cotters can only be grasped on one side for attachment or removal. In other words, the prior art cotter has only one gripping portion. The spring clip cotter also lacks a positive locking mechanism for more securely attaching the cotter to the pin, post or stud. In an environment where the cotter is exposed to excessive shock, vibration and stress, the cotter may come free from the pin, post or stud.
Improvements to the cotter have been disclosed in previous patents. See for example, U.S. Pat. No. 4,592,689 entitled Ring Spring Cotter issued on Jun. 3, 1986 and assigned to the same assignee as the present invention. The Ring Spring Cotter design discloses a pin in the form of a "figure 8". A locking mechanism is provided where the end of the pin is bent to lock the pin in its closed position. Other typical examples of prior art cotters are described in U.S. Pat. No. 5,662,446, entitled Easy Lock Safety Spring Cotter Pin issued to Louis R. Han on Sep. 2, 1997; U.S. Pat. No. 5,217,338, entitled Twist Type Locking Pin issued to Richard S. Czubek on Jun. 8, 1993; and U.S. Pat. No. 4,298,299, entitled Hairpin Cotter Key issued to James R. Quarles on Nov. 3, 1981. Each of these prior art devices requires an additional "locking step" to positively lock the cotter onto the pin, post or stud after installation.
This invention relates to a unique and novel cotter pin design that is easy to install, easy to remove, and provides a locking feature without requiring further or additional steps to lock the pin.
It is an object of the present invention to provide a cotter pin the can be easily installed on a post, shaft, bolt or other device. Another object of the invention is to provide a cotter that is easy to remove from its installation. It is a further object of this invention to provide a cotter that is securely attached to its mating component so that the cotter does come lose as a result of vibration or shock.